1. Field of the Invention
The present invention relates to a light emitting diode (LED) package, and more particularly, to an LED package including lead frames on which an LED chip is mounted and a supporting member for supporting the lead frames, wherein the structure of the supporting member, and furthermore, the structure of lead frames are improved.
2. Description of the Related Art
An LED is an element in which electrons or holes are combined in a P-N semiconductor junction structure by application of current thereby emitting certain light. The LED is typically formed to have a package structure, in which an LED chip is mounted, and is frequently referred to as an “LED package.” Such an LED package is generally mounted on a printed circuit board (PCB) and receives current applied from electrodes formed on the PCB to thereby emit light.
In an LED package, heat generated from an LED chip has a direct influence on the light emitting performance and life span of the LED package. The reason is that when heat generated from the LED chip remains for a long period of time, dislocation and mismatch occur in a crystal structure of the LED chip.
Accordingly, conventional technologies for promoting dissipation of heat generated from an LED chip have been suggested. A representative of these technologies is an LED package, in which an LED chip is not mounted on a lead frame, but a heat sink slug made of a metallic material with superior thermal conductivity is inserted into a package body and an LED chip is then mounted on the heat sink slug.
However, in the conventional LED package, since the heat sink slug has a volume relatively larger than a heat sink area through which the heat sink slug is exposed to the outside, its use is restricted if the heat sink slug is not made of a expensive thermal conductive material. Further, there is a problem in that much cumbersomeness in a process may occur when mounting the heat sink slug. Furthermore, the heat sink slug may become a cause of hindering compactness of the LED package.
A conventional LED package with a double or multiple molding structure, in which a molding member for protecting an LED chip is formed to have a plurality of resin portions, has been known. The conventional LED package has a single large cavity for opening both portions of first and second lead frames, wherein the portion of the first lead frame has the LED chip mounted thereon, and the portion of the second lead frame is connected to the LED chip by a bonding wire. In such an LED package, a first resin portion made of, for example, silicon resin is first formed in the single cavity, and an epoxy- or silicon-based resin with excellent strength is then formed to cover the entire first resin portion, wherein the first resin portion is strong for thermal impact, and furthermore, contains a phosphor.
However, in the conventional LED package, since the first resin portion is formed by injecting a liquid resin broadly in a large-sized cavity without a clear boundary with the second resin portion to be formed on the first resin portion, the interface between the first and second resin portions is nonuniformly defined, which causes lowering of light efficiency and performance degradation of the LED package due to the lowering of light efficiency. Further, although it is effective that a phosphor used in color mixture of light and color conversion of light due to the color mixture of light is concentrated on a circumference of an LED chip, the phosphor is unnecessarily broadly distributed in the broad cavity. Therefore, the color conversion efficiency of light may be lowered, and furthermore, waste of the phosphor may be caused.